Feast and Famine Flashcards
What are the 3 ways in which metabolic pathways are regulated
- allosteric effectors
- covalent modification
- changes in amount of key enzymes
function of acetyl COA
activate pyruvate carboxylase
inhibits pyruvate dehydrogenase
function of AMP
activate AMPK
inhibit gluconeogensis, protein synthesis, lipogensis, cholesterol synthesis
function of cirtrate
activate acetyl-CoA carbozylase (FA synthesis)
inhibits PFK1 and PFK2 (glycolysis)
functino of fuctose 2,6 bp
activate PFK1
inhibits F11,6BPase
function of fructose 1,6 bp
activate pyruvate kinase
function of glucose
actiate glucokinase
function of malonyl-CoA
inhibit CPT I (FA degration)
functino of cAMP
activate protein kinase A
incrase glycogenolysis, gluconeogensis
inhibit glycolysis, lipogensis
affect of fatty acids
induce gene for FA ozidation and keton synthesis by PPRE
affect of glucocagon
induces genes for gluconeogensis bia CRE
represses genes for lipid synthesis via CRE
affect of insulin
induces genes for lipid syntheiss bia SRE
represses genes for gluconeogensis and FA oxidation via IRE
limitations of fatty acids as energy
- requires O2
- can’t cross bbb
- can’t be converted into glucose
advantages of glucose
can be catabolized quickly w/o oxygen
-can cross bbb
limitation of glucose
small stores
limitations of amino acids
no storage
metabolism of RBCs
convert glucose to lactate
what do muscles prefer for energy metabolism
fatty acids
What else can muscles use for energy
glucose
ketone bodies
can muscles function anaerobically
yes, briefly
can muscles convert amino acids to glucose
no - happens in liver
Does the heart story energy
no
can the heart function anaerobically
no
what type of fuel does the heart prefer
fatty acids
what fuel does the brain use
glucose, in severe stravation it can use ketones
what fuel does the liver use
fatty acids, glucose, amino acids, and lactate
what does liver store
glycogen
excess glucose is converted by the liver into what
VLDLs
what releases fatty acids and glycerol
adipose tissue
what happens during refeeding
electrolyte problems
what 2 conditions need to be considered when refeeding
lack of digestive enzymes
lack of intracellular phosphate
after the first 10-20 second of excerise what happens
muscle funciton is driven by ATP/creatine-phospahte reserves
after 20 seconds of excerise what happens
muscle function is supported by fatty acid and glucose metabolism
what happens after an hour of excerise
metabolism increases fatty acid utilization
what happens after 2 hours of exercise
glycogen stores are exhausted and energy is drawn from fatty acid oxidation
